Hemodialysis is a process by which microscopic toxins are removed from the blood using a filtering membrane such as a dialyzer. Typically, hemodialysis is administered in intermittent three to four hours sessions, which take place two or three times per week. However, there exists a growing body of research that prefers continuous renal replacement therapy (CRRT) over intermittent dialysis since far more toxins can be removed from the blood using CRRT seven days a week, twenty-four hours a day. Some advantages of CRRT include a decreased rate of morbidity and expected mortality, a decrease in the amount of medications required and a decrease in fluid intake and dietary restrictions.
CRRT utilizes machines that provide around the clock dialysis, hemofiltration or a combination of both. However, CRRT machines are cumbersome, heavy and must be hooked to electrical outlets and several feet of tubing. In addition, these machines require a continuous supply of gallons of fresh dialysate fluid. Further, a CRRT patient must remain connected to the CRRT machine for many hours, limiting his or her ability to perform normal every day activities.
An addition problem with CRRT, is that daily reconnection to the CRRT machine requires accessing blood flow by puncturing a large blood vessel forming an arteriovenous shunt. These shunts only last for limited periods of time and are subject to infection, clotting and other complications that result in numerous hospitalizations and repeated surgical interventions.
Unsuccessful attempts have been made to create a wearable dialysis device employing the idea of CRRT. Because of the bulky nature of typical dialyzers and associated sorbent devices, the concept of a wearable CRRT device has yet to become a reality for most dialysis patients. In view of the above disadvantages, there continues to be a substantial need for a portable, wearable CRRT device, which can which can be used continually, 24 hours a day, seven days a week.